Covered elastic strand and fabric



Oct. 26-, 1937.

s. c. LILLEY COVERED ELASTIC STRAND AND FABRIC File d Jan. 27, 1936-Patented Oct. 26, 1937 UNITED STATES PATENT oFi-"ica COVERED ELASTICsmANn AND Fannie I Samuel C. Lilley, Hamden, Conn, asslgnor to TheAmerican Mills Company, West Haven, Conn.,

a corporation of Connecticut Application January 21, 1936, sci-in No.60,896

This invention relates to improvement incovered elastic strands andfabrics incorporating the same, and constitutes an improvement upon theelastic strands and fabric disclosed in my co- 6 pending application,filed December 23, 1933,

Serial No. 703,795.

The present invention contemplates an improved elastic strand adapted tobe woven, knitted or otherwise incorporated into fabrics, and

comprising an inherently-short-stretch (not more than about 300%)elastic core of rubber or equivalent material and a covering of fibrousflock;

One of the objects of the present invention is to provide a superiorlow-cost and durable covered elastic strand, comprising aninherentlyshort-stretch elastic core and a covering of flock, i.-e.-,amorphically-disposed fibers secured to the surface thereof. e

, A still further object is to provide a superior elastic strandcomprising an elastic core of rubberfor equivalent material andv acovering offibrous flock cemented thereto, and in which the elastic coreis of the short-stretch character referred' to and which core willminimize the pOssi-' bility of a rupture occurring in the bond betweenthe covering and the core.

Another object is to provide a superior flockcovered elastic strandcharacterized by the rapid build-up of tension therein when stretched toas little as three hundred per cent.

' Still another object of the present invention is to provide a coveredelastic strand which may be woven into a fabric with superiorconvenience and facility. v p. Still another object is to provide asuperior fabric incorporating elastic strands of the character referredto.

With the above and other objects in view, as will appear to thoseskilled in the art from the following, considered in coniunctlon, withthe accompanying drawing and appended claims, the pres-- ent inventionincludes all features disclosed therein which are novel over the priorart. In the accompa yin drawing:

Fig.1 is an enlarged-scale elevatlonal view 'of one form which a flockedelastic strand may assume in accordance with the present invention;

Fig. 2 is a transverse sectional view taken on Y the line 2-2 of Fig. 1;

Fig. 3 is a view in side elevation of the strand when. stretched tosubstantially the limitof its extensibility;

Fig. 4 is 'a schematic view illustrating a fabric incorporating theimproved elastic strands; and

Fig.5 is a sectional view taken on the-line 5-5 of Fig. 4.

The elastic strand ofthe present invention in'-- I cludes a strand-likecore III of rubber or equiv--' alent elastic'material, which may be ofrectangu- 5 lar, roundv or other cross-sectional form, and

which is characterized by a very rapid build-up of its tension inasmuchas ithas an elastic limit not substantially in excess of three hundredper cent (3.00%), that is to say, for imtance, a one- 10 inch length ofelastic core which would reach its elastic limit when extended toapproximately four inches. a

The elastic core I 0 is provided with a coating I l of elastic adhesivewhich may be applied in any 15 approved manner, such, for instance, asby passing the strand-like core through a bath of elastic adhesive. a

After the coating ll of elastic adhesive has been applied to the strandand before the said adhesive 20 is dried or completely cured, a coatingor skin I! of flock or amorphically-arranged fibers is applied in anyapproved manner, such, for instance, as by blowing the fibrousfiockagainst the now tacky or sticky strand. The fibrous material or 25 flockemployed may vary widely. in character, de-

tic cement or adhesive II and flock 12,, may now 35 be dried or cured inarrv one of a variety of manners, such, for instance-as by passing thesame through aheated chamber.

The above-described process. for producing the improvedinherently-short-stretch elastic strands 40 is a preferable one, thoughit will be obvious that, if desired, the fibrous flock may be applied tothe tacky surface of an elastic core prior to its curing orvulcanization and while its surface is still sumciently tackyto receiveand hold 45v the fibrous flock-coating. If desired, an elastic core mayhave its surface rendered tacky by heat or by a light application ofsolvents prior to j the application of the fibrous flock. Under themodes of manufacture, Just referred to, while 50 no separate coating 'ofadhesive material is applied to the short-stretch elastic core,nevertheless the fibrous coating is cemented or secured in place.

Although the elastic core maybe composed of 55 a wide variety ofmaterials, the following compound, after being cured at 260 F. m aboutforty-five minutes, has been found t'o produce a highly satisfactoryelastic core having an elastic limit of about two hundred fifty per cent(250%) and a tensile strength in the neighborhood of forty-two hundred(4200) pounds per square inch of cross-sectional area, thecross-sectional area referred to being based upon therelaxed core:

Symmetrical di-beta-naphthyl-para-phenyl- -enediame 1 By reducing theamount of carbon blackin the above formula, an elastic core may beproduced having an elongation of approximately three hundred per cent(300%) before the breaking point or the point of permanent distortion isreached.

By altering the above-given formula so as to include therein 150 parts'by weight of carbon black rather than the 50 parts specified, a ru'bbercore may be produced having an elongation of about one hundred per cent(100%) before the breaking point is reached, and having a tensilestrength of about three thousand (3,000) pounds. Similarly, by alteringthe carbon black constituent so that it constitutes 200 parts of themixture by weight, elastic cores having an elastic limit of about fiftyper cent (50%) may be produced with a tensile strength of about twothousand (2,000) pounds per square inch of crosssectional area. Cores ofthis latter degree of elongation represent about the minimumcontemplated.

An almost limitless variety of elastic cores of I the short-stretchcharacter with which this invention is concerned may be produced bysuitably compounding the'materials from which the elastic cores aremade. Inasmuch as such varieties of short-stretch rubber cores are toonumerous to set forth in detail therein, it is suflicient for thepresent purpose to say that, should it be desired to produce elasticcores having other specific degrees of extensibility than thosespecifically referred to above, the proportion of carbon black orequivalent material maybe varied accordingly, in a manner as may bereadily deduced from the foregoing specific examples. 1

Another compound which may be mentioned as being suitable for theproduction of elastic cores in accordance with this invention, whencured for about forty-five (45) minutes at approximately 260 F., is asfollows:

. Parts by weight Rubber. 100 Sulphur 3% Stearic ar-id 1 Symmetricaldi-beta-naphthyl-para-phen-' ylenediame 1 Zinc sulphide 5Phenylhydrazine V 90% zinc salt of mercaptobenzcthiazole 1 10%di-ortho-tolylguanidine; I Zinc oxide 5 Methylacrylic ester 20 Returningnow to the subject. of the adhesives (preferably elastic) forsecuring oradhering the coating or skin -I2 of flock in place to the core,

it has been found that rubber latex, water-dis-.

persed rubber, natural rubber solutions, syn-- thetic rubber solutions,etc., are suitable and may be used with or without vulcanizing material,vulcanizing accelerators, fillers, pigments, coloring matter, etc. Byway of example, an elastic adhesive solution which has been found verysatisfactory consists of approximately twenty per cent (20%) by weightof rubber, twenty per cent (20%) filler, pigment and vulcanizingmaterials, and the balance of volatile rubber solvents. J

The strand as now supplied with an anticreep coating or skin l2 ofamorphically-arranged fibers, is suitable for incorporation into woven,knitted or other fabrics. Woven, as well as other elastic fabrics intowhich the flocked elastic strand of the present invention may beincorporated may assume an almost infinite variety of patterns. In theelastic fabric shown in Figs. 4 and 5, a plurality of the flockedelastic strands iii are arranged parallel and spaced from. each other.

Parallel with the elastic strands I3 are a plurality of warp strands l4formed of cotton, rayon, silk or other suitable textile material.

[3 and H, just described, area crosswise series of weft or filler picks15. It hasbeen found desirable under some conditions to interweave thehigh-tension short-stretch flocked elastic strands [3 with the warpstrands l4 and the weft picks l5, while the said elastic strands are ina substantially-relaxed condition.

Owing to the very rapid build-up of the tension in the elastic core ofmy improved elastic strands (the maximum tension being reached at about300% extensibility), any tendency for a rupture to occur in the bondbetween the said core and the fibrous flock-coating is so minimized asto be negligible despite the repeated andcontinuous stretching andrelaxing of such strands. Furthermore-it has been found that owing toIntermeshed with the strands the rapid build-up in tension, abovereferred to,

The invention may be carried out in other spe cific ways than thoseherein set forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments aretherefore to be considered in all respects as illustrative and notrestrictive, and all I changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

' I claim:

1. An inherently-short stretch covered elastic strand characterized bythe rapid build-up of its tension when stretched and adapted to beincorporated into fabrics, the said covered elastic strand comprising ashort-stretch elastic core of rubber-like material and a protectivecoating of fibrous flock secured to the surface of the said core aroundthe perimeter thereof, the said shortaoeaam stretch elastic coreincluding sufficient stretch resisting material to cause said core tohave its maximum tension when extended to a degree not materialy inexcess cf'three hundred percent of strand comprising a short-stretchelastic core of rubber-like material and .a protective coating .offibrous flock elastically secured to the surface of the said core aroundthe perimeter thereof, the

said short-stretch elastic core including sufficient stretch resistingmaterial to cause said core to have its maximum tension when extended toa degree not materially in excess of three hundred per cent of itsnormal relaxed length.

3. An inherently-short-stretch covered elastic strand characterized bythe rapid build-up of its tension when stretched and-adapted to beincorporated' I into fabrics, the said covered elastic strand comprisinga short-stretch elastic core of rubber-like material and a. protectivecoating of fibrous flock secured to the surface of the said core aroundthe perimeter thereof, the said shortstretch elastic core includingsufllcient stretch resisting material to cause said core to'have itsmaximum tension when extended to a degree not materially in excess oftwo hundred per centof its normal relaxed length.

4. An inherently-short-stretch covered elastic strand-characterizedbythe rapid build-up of its tension when stretched and adapted to beincur-- porated into fabrics, the said covered elastic strand comprisinga short-stretch elastic core of rubber-like material and a protectivecoating of fibrous flock elastically secured to the surface of the saidcore around the perimeter thereof, the said short-stretch elastic coreincluding sufliclent stretch-resisting material to cause said core tohave its maximum tension when extended to a degree not materially inexcess of two'hundred per cent of its normal relaxed length.

5. An inherently-short-stretch covered elastic.

strand characterized by the rapid build-up of its tension when stretchedandadapted to be incorporated into fabrics, the said covered elasticstrand comprising a short-stretch elastic core of rubber-like materialand a protective coating of fibrous flock secured to the surface of thesaid core around the perimeter thereof, the said shortstretch elasticcore including suflicient stretch-resisting -material to cause said coreto have its maximum tension when extended to a degree not materially inexcess of one hundred per cent of its normal relaxed length. A

6. An inherently-short-stretch covered elastic strand characterized bythe rapid build-up of its tension when stretched and adapted to beincorporated into fabrics, the said covered elastic strand comprising ashort-stretch elastic core of rubber-like material and a protectivecoating of fibrous flock elastically secured to the surface of the saidcore around the perimeter thereof, the said short-stretch elastic coreincluding suflicient stretch-resisting material to cause said core tohave its maximum tension when extended to a degree not materially inexcess of one hundred per cent of its normal relaxed length.

I. An elastic fabric having incorporated therein a plurality ofinherently-short-stretch elastic strands, each comprising ashort-stretch elastic core of rubber-like material and a coating. offibrous flock secured to the surface of the said core around theperimeter thereof, the said short-stretch elastic, core includingsuilicien't stretch-resisting material to cause said core to have anextensibility not materially in excess of three hundred per cent of itsnormal relaxed length; v I

8. An elastic fabric having incorporated therein a plurality ofinherently-sho'rt-stretch elastic strands each comprising ashort-stretch elastic core of rubber-like material and acoating offibrous flock secured to the surface of the said core aroundtheperimeter thereof, the said short-stretch elastic core includingsufllcient stretch-resisting material to cause said core tohave anextensibility not materially in excess of two hundred per cent of itsnormal relaxed length.

9. An elastic fabric having incorporated therein a plurality ofinherently-short-stretch elastic strands, each comprising ashort-stretch elastic core of rubber-like material and a coating offibrous flock secured to the surface of the said core around theperimeter thereof, the said shortstretch elastic core includingsuflicient stretchresisting material to cause said core to have anextensibility not materially in excess of one hundred per cent of itsnormal relaxed length.

' SAMUEL C. mm.

